Reigate recorded a max gust of 36 mph last night as a vigorous ana-cold front produced a SQUALL LINE of extra heavy rain and gusty winds that rapidly crossed the country from west to east. Needless to say, the squall line reduced in strength as it arrived in Reigate and the SE but we still experienced some gusty winds early on. Nothing like as strong as the 80mph+ winds further west in Wales with associated hail. An ana-front is where the warm sector air is forced to rise more vigorously than “usual”, in this case due to a strong jetstream encouraging uplift of air from the surface due to divergence and rapidly falling pressure aloft. This literally “hoovers” air off the ground and produces lots of condensation, thick cumulonimbus clouds and plenty of heavy rain. Wind max during this storm for UK: S Uist 90mph; Plymouth 85mph. Other high winds include:

max gusts assoc with cold front

The culprit was the LOW pressure shown below in the UKMO analysis chart for 18 Dec. A cause of this extra vigorous cold front was cold Polar air originating from Canada. Spot the brisk W/NW winds following closely behind the front.

What next? There’s a calm period with a bright pleasant cool day coming up before more windy weather hits late Fri and heavy rain early this weekend. A powerful jetstream is making for some stormy weather in the run up to Christmas. There is the threat of a Channel storm around Christmas Day with possible heavy rain and gales for the south. Or the ECM if bringing in a very intense storm for the NW of the UK on Xmas Eve. Take your pick!